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Flashing detail for exterior insulated gable wall and roof

Salesi | Posted in General Questions on

Our new house will be 1-1/2 stories with a gable end meeting a roof covering a porch. If we build the gable wall out of 2×6 with 2″ of either polyiso  foam board or 2″ of comfort board 80, with a 1×3 rain screen, how would I flash the intersection of the roof line and the wall? Would I put a piece of bent aluminum flashing on top of the rain screen and meeting the roof line? Or would I put the flashing on the sheathing with WRB covering the leg going up the wall and the other leg extending out beyond the siding on top of the shingles?

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  1. GBA Editor
    Brian Pontolilo | | #1

    Hi Salesi,

    The wall leg of flashing at a roof to wall intersection, whether it is step flashing or continuous flashing, should be tucked beneath the WRB to divert water out from the drainage plane. This may mean bending custom flashing for your assembly.

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